Automatic ball float tank seal



Aug. 13, 1940.

E. P. SHAFT 2,211,296

AUTOMATIC BALL FLOAT TANK SEAL I Filed April 25, 1939 Inventor A itorneys Patented Aug. 13, 1940 UNITED STATES PATENT OFFlCE 1 Claim.

This invention relates to an automatic float seal for the outlet pipe of a liquid tank, and has for the primary object the provision of a device of this character which will seal closed an' outlet pipe of a tank with the liquid in said tank at a predetermined level to prevent air from entering the outlet pipe and forming an air lock therein or from reaching a supply line operated by a suction pump and to which the tank may be one of the supplies therefor.

Another object of this invention is the provision of a device ofv the above stated character which will successfully operate without a ground or especially constructed seat therefor and which may be easily adjusted to close the outlet pipe at varying liquid levels within the tank and which may be readily installed in the latter by a single mechanic located outwardly of the tank obviating the necessity of the mechanic or his helper from entering the tank in order to make installation or adjustment.

With these and other objects in view, the invention consists in certain other novel features of construction, combination and arrangement of parts to be hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawing, in which-- Figure 1 is a fragmentary vertical sectional view illustrating an automatic ball float seal adapted to said tank and constructed in accordance with my invention.

Figure 2 is a fragmentary vertical sectional view illustrating the means of mounting a guide tube within the tank, adjacent the man opening thereof.

Figure 3 is a vertical sectional view illustrating the ball float.

Referring in detail to the drawing, the numeral 5 indicates a supply tank which may form a series of like devices for furnishing liquid to a supply line'(not shown) and frequently operated by a suction pump. However, this tank need not 4 be connected to a supply line of the character set forth and may be utilized as asingle liquid supply for any type of device, the outlet pipe of the tank being indicated by the character 6 and secured to said tank by a sleeve-like fitting l, the inner end of which is disposed within the tank at a selected distance above the bottom of the tank and which will provide a seat for a ball float seal 8 arranged in the tank and forming the subject matter of the present invention.

The inner end of the sleeve-like fitting I is formed with a straight end for coaction with the ball float seal and it will be apparent that it is not necessary to utilize in conjunction with the seal a specially constructed seat.

The ball float seal 8 consists of an inner 5 spherical shaped shell 9 provided in the wall thereof with an internally screw threaded inwardly extending neck 10 in which is threaded a closure plug H equipped with an eye l2. Arranged in the shell 9 opposite the neck i9 is a 10 weight l3, the purpose of which is to maintain the shell floating in liquid with the neck I0 disposed uppermost. By having the plug the amount of liquid in the shell 9 may be varied for the purpose of varying the depth the shell 15 will float in the liquid at the surface of said' liquid. It will be seen by increasing and decreasing the amount of liquid in the shell the latter will partially submerge itself to a greater or less extent in the liquid and thereby bring about closing of the outlet pipe at varying levels of the liquid in the tank.

A covering I4 is applied to the shell 9 and covers the entire shell and is preferably constructed of spongy rubber or some other suitable soft 25 material so that when the ball float comes in contact with the sleeve-like fitting 1 it will form an effective seal therewith.

A chain or some other suitable flexible element I5 is attached to the eye l2 and is adapted 30 to extend through a guide tube It arranged in the tank and has secured to its free end a finger piece H. The guide tube I6 has one end threaded in a supporting sleeve I8 arranged adjacent or within the man opening of the tank. The 5 sleeve l8 has an attaching bracket l9 bolted or otherwise secured on the tank. The flexible element and the guide tube 16 act as a restraining means for the movement of the ball float 8 within the tank to prevent the ball float from becoming entangled with obstructions that may 40 be in the tank for the support or reinforcement of the walls of said tank. Also, the flexible element provides a convenient means for disengaging the ball float from the seated position with the sleeve-like fitting 1, should the suction in the pipe 6 act to maintain the ball float seated after the filling of the tank with the liquid.

The weighted ball float when the tank is substantially filled with liquid will float in said liq- 50 uid restrained by the flexible element and at a distance above the sleeve-like fitting i so as not to obstruct the outflow of liquid from the tank. However, when the liquid reaches a predetermined level in the tank above the outlet pipe the 55 flow of liquid from the tank carries the ball float into seated engagement with the fitting l and thereby closes the latter maintaining the level of the liquid a limited distance above the fitting i so that air cannot enter the pipe 6.

From the foregoing description, when taken in connection with the drawing, it will be seen that this device may be easily and quickly installed in a tank without the necessity of the mechanic entering the tank and will successfully operate without a specially constructed seat therefor.

It is believed that the foregoing description, when taken in connection with the drawing, will full set forth the construction and advantages of this invention to those skilled in the art to which such device relates, so that further detailed description will not be required.

What I claim is:

In combination with a fluid supply tank having a manhole in the top thereof and provided with an outlet pipe extending therein adjacent the bottom of said tank, a float in said tank to form a seal for the outlet pipe by engaging with the end of the latter when the level of the fluid nears the outlet pipe, a bracket mounted in the tank adjacent the manhole and including an internally screw threaded sleeve, a vertically arranged guide tube having the upper end thereof threaded in the sleeve and terminating above the outlet pipe and adjustable towards and from said outlet pipe by being threaded relative to said bracket, a flexible element connected to said float and extending through the tube, and a finger piece connected to the free end of the flexl5 ible element and supported by the tube in a position to be reached by a person through said manhole while in a position exteriorly of the 

